Fuel-injector for internal-combustion engines.



G. F. MURPHY. FUEL INJECTOR FOR INTERNAL COMBUSTION ENGINES. APPLICATIONFILED JULYIS, 1907.

989,026. Patented Apr. 11, 1911.

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FUEL INJECTOR FOR INTERNAL COMBUSTION ENGINES. APPLICATION FILED JULY13, 1901.

' 989,026, Patented Apr. 11, 1911.

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GEORGE E. MURPHY, OF JERSEY .COMI'ANY, OF PROVIDENCE, RHOIYE ISLAND,

CITY, JE'B SIiY, ASSIGNOR' T FUEL OIL ENGINE A CORPORATION OF RHODE-ISLAND.

I'UEL-INJECTOR FOR INTERNAL-COMBUSTION EllGINES.

. To all whom it my ro'rwem:

' for Internal-Combustion Engines,

Be it known that I, Gnoncn F. MURPHY, a citizen of the United States,residing at Jersey City, in the county of Hudson and State of NewJersey, have'invented certain new and useful Improvements inFuel-Injectors of which the following is a full, clear, and exactdescription. My invention relates to internal combustion engines, andparticularly of that type in which liquid fuel is injected into acylinder in. which pure air has been highly compressed. a

The present invention relates particularly -toa form of oil injectionmechanism by be-eontrolled hich engines of this class may as evenly andperfectly as the best steam engines having a governor controlledcut-oil.

- The invention consists therefore in the features of" construction andcombination as hereinafter set forth and shown, and

finally particularly pointed out in the ap ended claims.

In the drawings: Figure 1 is a side elevation of an oil injectionmechanism embodying the principles of my invention in place upon thecylinder of an engine; Fig. 2 is a sectional view of'the same; Figs. 3and l are detail views showing certain cam levers or parts; Fig. 5 is aview of the oil injection mechanism removed from the cylinder andlooking from the left in Fig. 1; Fig. 6 is a horizontal sectional viewof the same on the line VI-VI of Fig. 5; Figm is a vertical sectionalview on the line VII-V1I of Fig. 6; Fig-8 is a detail view showing theappearance of the bottom end or face of the oil injection mechanism.

The general principle of operation of the fuel injection engine is basedon the fact that if air is compressed to a very high degree, say 30 or35 atmospheres, the temper ature thereof becomes so elevated that anyordinary oil or fuel injected therein or subjected thereto, becomesignited and burns, adding its heat and energy to the compressed air. Inordinary practice, the pure air is compressed in a cylinder to about 35atmosphere pressure, and oil is, thereupon injected at the beginning ofthe expansion Specification of Letters Patent. Application and m 13,1907. serial No. 323,570.

be controlled by which may Patented Apr. 11, 1911.

stroke of the piston. The oil burns or combines with the air almostinstantly when injected, so that the rate of combustion is determined bythe rate of injection of the oil. When the oil supply is cut off, thecombustion ceases and thereafter the expansion merely takes placeadiabatically as in a steam engine. The eriodof the'oil cut-ofi'relative to the engine stroke is therefore somewhat analogous to thecut-off of steam in asteam engine, and may conveniently a governor. Themechanism for injecting and cutting ofi' the oil should be veryglarfect, since the slightest deviation from t e feed of exactly correctquantities at exactly the right time, produces a very great disturbanceon the operation of the engine. The present invention therefore aims tosecure the very greatest exactness in the feed control and cut oil'ofthe oil supply.

Referring to the drawings in. which like parts are designated by thesame reference sign, 1 indicates the cylinder of an engine, be of anysuitable character, as, for example, described in my co-pend-i'application, Serial No. 381,920, filed Juy 2, 1907; 2 denotes thepiston movable therein and approaching the head 3 of the cyiinder veryclosely in its movement so that the space into which the air may becompressed is extremely restricted, and whereby the compression iselevated to a'very high degree. The piston 2 and the head 3 may be cutaway slightly at 4' soas to provide a convenient cavity or chamber intowhich the oil from the injector is received. At a point. communicatingwith the recesses 4- there is provided a hole 5, through the wall of thecylinder.

6 denotes a frame or casin adapted to be received on top of the cylin erand. having a protuberance 7 which fits' tightly in the hole 5. Thisframe or casin may be secured on the cylinder in any suita le way.

Within the protuberance 7, of ,the frame.

The cavity 9 communicates with the cavity 10 by a passage 12, whilethe-cavity 10 communicates with the cylinder of the engine through apassage 13.

14 and 15 denote needles or valves which cooperate with the valve seats11, 11', and

closethe respective passages 12 .and 13. I

have illustrated a construction of the passage.

tend upward through their cavities 9 and 10 and through glands orstuffing boxes 18, 18, in the frame or casing 6. At their upper endsthese valve members are extended or enlarged to form cups 19, 19', whichreceive the springs 20, 21". 21 indicate abutments for these springswhich are heldin place by an extension '22 of the frame 6. This relation'is such that in the absence of certain mechanism hereinafter described,the needle valves 14 and-15 are pressed downward on their seats 11, 11so as to close the passages 12 and 13 respectively.

The mechanism for raising the needle valves off their seats will be bestunderstood from a consideration of Fig. 2. The frame 6 has a loosetransverse shaft or spindle 23 therein, on which are loosely pivoted apair of cam levers 24 and 25 (see particularly Figs. ,3 and 4). Theselevers have openings 26 therein through which pass the needle valves 14and 15. The upper sides of these levers are adapted'to be brought tobear against the heads or enlargements 19, 19', of the needle valves, byreason of which the needle valves may be raised off their seats. Theouter ends of these levers 24, 25, are

provided with the respective cam surfaces 27, 27 and 28, 28; camsurfaces 27, 27

being adapted for engagement with a roller 29 and surfaces 28, 28 beingcorrespondingly adapted for engagement with a roller 29, both rollersbeing mounted on a single rock 'arm 30. -This rock arm is convenientlymade forked or bifurcated, as shown, so as to more rigidly support therollers, and is] pivoted on a shaft 31, in the frame 6.

32 denotes a lateral extension of the rock arm which is engaged by aspring 33, to impel the rock arm'normally outward, or to the left, inFigs. 1 and 2.

The rock arm 30 terminates at its outer end in the form of a lip 34, andwhich is adapted to be engaged by a hook 35, pivoted to a rock arm 36,fixed to the transverse shaft 23 already described. This transverseshafthas an additional crank or arm 37 thereon, extending downward fromone of its ends, and by means of which to an eccentric'on the crankshaft, or any it may be. swung back and forth by link 38, extending Ycylinder.

shown). In this Way the shaft 23 is rocked back and forth at eachrevolution of the engine and the rock arm 30 is correspondingly movedunder the influence of the hook 35. The engagement of the hook 35, withthe rock arm 30- is only made during the forward movement of the hook,the latter being then disengaged to permit the rock arm 30 to return byits spring 33. The mechanism for this purpose preferably comprises abifurcated swinging arm 39, having a roller 38, on which the lowersurface of the hook 35 rides.

40 denotes a link extending to any convenient governor (not shown), bywhich the position of the arm 39 isdeterniined and varied.

The operation is as follows: Supposing the piston 2 has moved to aboutthe limit ofits compression stroke, it becomes necessary for the oil tobe injected in an amount suitable to the load of the engine at thistime. The adjustment 'of the parts is such that the link 38 is beingpulled at this time by its eccentric, or other means (not shown), andthe hook 35 is effective to draw inward the rock arm 80 so that roller29, which is normally in engagement with cam surface 27 is moved intoengagement with cam surface 27, while roller 29, which correspondinglyis normally in engagement with cam surface 28, is moved into engagementwithcam surface 28. As apparent from Figs. 3 and 4,

the cam surface 28 is more abruptly inclined ,to the path of movement ofthe roller than is cam surface 27. Hence when the rollers move fromtheir initial or resting positions, and the levers 24 and 25 are therebydisplaced upwardly, lever 24 will swing upwardly more slowly than willlever 25 and will therefore contact with and begin to raise cup 19 aftercup 19 has been raised by its lever 25. In other words, lever 25 inraising lifts'needle valve 15 and lever 24 lifts needle valve 14, butvalve 15 is invariably lifted from its seat 11 before valve 14 is movedfrom its seat 11. The chamber or cavity 10 is in permanent communicationwith the air pressure reservoir througha duct or passage 41, so that theinstant valve 15 is raised air flows through port 11. Flow of air alone,however, continues for but a brief interval since the cavity 9, in whichis disposed the valve14, is in permanent communication with an oilpressure reservoir through a duct or passage 42 and when valve 14raises, as it does immediately after valve 15 has. been raised, oil willflow through port 11, and passage 12 and will be entrained with the airpassing through port 11 and immediately driven into the engine It isevident that the pressures in other convenient operating mechanism (notmediately cylinder, and for this purpose it is necessary the oiland airreservoirs mustbe higher than the compression in the cylinder in orderto secure this result. The current of air breaks u or atomizes the oiljet, which action is assisted and increased by the pins or projections17 in the passage 18. '.This is important, because the oil should beimburnedi or consumed in the engine to have the oil injected in a finelydivided or atomized condition. As the hook 35 continues its forwardmovement (to the right), the rock arm swings through an arc, as shown indotted lines in Fig. 2. The hook oscillates slightly in a vertical planeto accommodate this movement which it can do on account of its pivotalconnection with the arm 36 and the slotted character of the swinging arm39. At the end of the movement, however, the hook 35 bears against andrides upon the roller 38, and as the foradvance of the air valve.

ward movement of arm 36 continues, the hook is'tripped off the edge ofthe lip 34. The rock arm 30 immediately returns with a very abruptmovement under the impulse of its spring 33, and the needle "alves 14.and t5 quickly close upon their seats. But it is evident that the needlevalve 15 will never close until 14 has properly seated itself. This isinsured by the character of the; cam faces 27 and 28 which tend toproduce a closure of the oil valve slightly in In other words, the airvalve is always allowing air to pass into the cylinder when the oilvalve is opened, while it is being held open, and when it is closed.-Accordingly, it is impossible for any oil to collect in the passage 10since such oil would be instantly blown out of this passage and into thecylinder by the current of air therethrough when the oil valve is open.

In the above description the roller 38, on which the hook 35 rides, hasbeen treated as if stationary. The position of this roller is. however,varied by the angular position of the swinging arm 39 controlled by thegovernor rod 40'. As the governor rod is pulled toward the left inFigs.1 and 2, it is'clear that the roller 38 is slightly elevated, and thehook 35 tripped off of the lip 34 at an earlier point in the stroke ofthe engine. The point of cut-off of the oil injection in the cylinder istherefore varied by the engine governor. t

It will be observed that the .cut-oif of the oil supply is exceedinglyabrupt, since all of the oil controlling parts are of comparativelysmall and light construction, and are assisted in their movement by anumber of controlling springs, as well as the force of gravity. Thesprings 20 and 20' are very strong since they have to resist thepressure which is always flowing ernor-controlled devices acting of thegases in the cylinder, so that these springs impel the needle valvesdownward quickly on their seats. As the cam levers 24 and 25 are free'to drop by their own weight these oppose no resistance to" the closingof the needle valves. If the pressure in the oil reservoir is differentfrom that in the air reservoir, no efiect on the operation is produced,because the two passages 41 and 42 are never open to one another, exceptat the time when they are both in communication with the cylinder. Atthis time the p-reponderating pressures in the oil and air reservoirsinsure a proper flow from each to the cylinder. The needle valve 14invariably closes the communication between the passages 41 and 42before theneedle 15 has shut off the communication from the c linder, sothat under no circumstances can e oil flow into the air reservoir or theair flow into the oil reservoir. These last named considerations areextremely important ones in practice, since at the pressure used, a dropor two of oil gettin into the air reservoir would burn and might causean extremely disastrous explosion.

In normal running the engine operates somewhat analogously to a steamengine, the cut-off occurring at a point depending on the engine load.As in steam engines, the sharpness of the cut-ofi is important from thestandpoint of efficiency. It is evident that these various features aswell as a very uniform feed of the oil, are secured by my abovedescribed mechanism.

What I claim, is

1. In a fuel injector for an internal combustion engine, means acting toinitially admit air and afterward liquid fuel. under pressure to theengine cylinder, and govon said uid fuel ier than means to invariablyout off the li at a point in the engine stroke ear the cut-off of theair.

2. In a fuel'injector for an internal combustion engine, a part having achamber opening into the engine cylinder, a needle valve closinginwardly toward the cylinder and spring impelled into a relation toclose such opening, means for raising said valve off the opening, andmeans for releasing the needle valve to close said opening.

3. In a fuel injector for an internal combustion engine. a part havingan opening for admitting liquid fuel to the engine cylinder, a needlevalve for closing said opening, a spring directly engaging the needlevalve to move it into closing relation, a cam lever for raising saidneedle valve off its seat, and means movable out of engagement with saidcam lever to permit an abrupt closing movement of the valve.

4. In a fuel injector for an internal combustion engine, means forfeeding oil tofthe engine cylinder, a needle valve for cutting off thefeed of oil, a sprin for impelling such needle valve into cut-orelation, a cam lever pivoted to engage said needle valve and raise itoff its seat, a rock arm engaging said cam lever, and means foroscillating said rock arm.

such needle valve intocut-o relation, a cam lever pivoted to engage saidneedle valve and raise it off its seat, a rock arm engagin said camlever, a hook for oscillating sai rock arm, and means'for tripping saidhook from its engagement with the rock arm.

6. In afuel injector for an internal combustion engine, means forfeeding oil to the engine cylinder, a needle valve for cutting 03 thefeed of oil, a sprin for impelling such needle valve into cut-orelation, a cam lever pivoted to engage said needle valve and raise itoff its seat, a rock arm engaging said cam lever, a hook for oscillatingsaid rock arm, and governor controlled means for tripping said hook fromits engagement with the rock arm. p 7 In a fuelinjector for an internalcombustion engine, a pair of valves for controlling air and liquid fuelrespectively, separate cam levers for raising said valves off theirseats, and a single means engaging said cam levers to move them intoengaging relation to the valves.

8. In a fuel injector for an internal combustion engine, a pair ofvalves for controlling theadmission .of fuel under pressure and airunder pressure to the cylinder, means for tripping said valvessuccessively into closing relation, and governor controlled means fordetermining the point of such action With respect to the engine stroke.

9. In a fuel injector for an internal com: bustion engine, valves forcontrolling the admission of air and liquid fuel to the cylinder,springs for impelling said valves into closingrelation, means forraising said valves into opening relation, and governor controlled meansfor releasing both valves, whereby they close on theirseats With anabrupt,movement.

10. In'a fuel injector for an internal combustion engine, a frame havinga cylindrical protuberanceadapted to fit in the Wall of the enginecylinder, chambers in said protuberance communicating With sources ofoiland air under pressure, respectively, needle valves in said chambersfor controlling the flow therefrom to the engine cylinder, springs forimpelling said needle valvesinto closing relation, separate cam leversfor raisingthe needle valves off their seats, and cam means for liftingthe needle valves in opposition to said springs. I

11. In a fuel injector for an internal combustion engine, a frame havinga cylindrical protuberance adapted to fit in the Wall of the. enginecylinder, chambers'in said protuberance communicating With sources ofoil and air under pressure respectively, needle gva'lves in saidchambers for controlling the flow therefrom to the engine cylinder,springs for impelling said needle valves into closing relation, separatecam levers for raising the needle valves. oif their seats, cam means forlifting the needle valves in opposition to said springs, and governorcontrolled means for tripping said cam means to permit the needle-valvesto close abruptly.

12. In a fuel injector for an internalcombustion engine, a valve forcontrolling the admission of liquid fuel to the engine cylinder, a camlever for raising said valve off its seat, a rock arm having a rollerengaging said cam lever, an arm having a hook engaging said rock arm,and means for oscillating said hook arm.

13. In a fuel injector for an internal combustion engine, a valve forcontrolling the admission of-liquid fuel to the engine cylinder, a camlever for raising said valve off its seat, a rock arm having a rollerengaging said cam lever, an arm having a hook engaging said rock arm,means for oscillating said hook arm, and means engaging said hook tolift it from its engagement with the rock arm whereby the needle valvecloses with an abrupt movement. 1

14:. In a fuel injectorfor an internal combustion engine, a needle valvefor controlling the admission of fuel to the cylinder, a

spring for 'impelling said needle valve into closing relation, a camlever for raising the needle valve, an outwardly spring impelled rockarm engaging said cam lever, means having a hook engaging said rock armand having an oscillating movement, and governor controlled means forlifting the hook and tripping it from its engagement With said rock arm.

15. In a fuel injector for an internal come bustion engine, a framehaving an air pas-, sage leading to the engine cylinder and having anoil passage leading to the air passage,

separate closing means adapted to be tripped to close said passages and'governor controlled means for-tripping said' separate means successivelyinto action.

16. In a fuel injector for an internal com bustion engine, a valve forcontrolling the admission offuel under pressure to the cylinder, meansfor raising saidvalve as its seat and maintaining it raised a constantpredetermined distance during a .portion of the forward engine stroke,and governor controlled means acting at variable points in such portionof the engine stroke for tripping said valve into closing relation, thedistance said valve is raised off its seat at the moment of closingbeing the same for all points of cut-ofi'.

17. In a fuel injector for an internal combustion engine, a part havinga passage for 10 the flow of liquid fuel, said passage having pins orprotuberances projecting radially therein, whereby the flow is broken upand the liquid fuel atomized.

In Witness whereof, I subscribe my signature, in the presence of twowitnesses.

GEORGE F. MURPHY.

-Witnesses:

WALDO M. CHAPIN, JAMES DAn'romo.

